SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a5626f045082fe173235b06ecb46d74c3b1be1ac8ed25b77ddca26bb39512fb1' 
  AND token = 'fsxYlljBFH2fwT8iZru5xRoQdL/Y1mqChxIDBGYQ1hM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00014

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}