SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5eed8574aad705ef48a2a749f1c4e347a1fe97dc86d89d6302c62c6bb3630b7b' 
  AND token = 'NdmxjOTo8QaOGRBQVlsfI12EwMdzwaYqnSrm3boo1LA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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