SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '425885433bf3fad8d71cd0bd0ed07cabd3806cdcc64746ed5a9bbc3fee64e02b' 
  AND token = 'PRl+u6/PQuHL7CVZJEatcviBxA6EWUly9FpGD1nEt5E=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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