SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '525f0e34bd0cab022daf67ca839ca35858bc048f99d1038a7df2d8816140dc79' 
  AND token = 'B7afdjm8XX2rjqxMQOQ2gZ5vgMEtD8/FkO5wxrAIPSc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

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