SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd41ac5733218fb077537fbbebf323e8cfc1f90043610b1cdae3a263de67fbd12' 
  AND token = 'bHTqMSUgb9r+OOghM+61cJpgAhLV4Fy4aeRl9fBIu40=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}