SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9e02e41fd7bf99324ff64609d325528c23a96b4a50b081f328bc8e91e211bb7d' 
  AND token = 'X/geG5fcHtySxtxLfITTBRUUEbRhlDzGrELDNamslM8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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