SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4b1df7da38efb45666b8f1891a7f38687d67747d1815894a9bbac79c56bb14e7' 
  AND token = 'Pk9yS7za+6DSbnZ3TNfZGSAjMiit9OSZGDmTja7r9hc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00045

JSON explain

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