SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e523d68c2de72d1ea632acc47acef0f10402221f5e7c154b2cca3b4caa05fac5' 
  AND token = 'tpo6phZC6JwHeNk5T0K5dbmCSvWTD0EQpkdQsIYBH1U=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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