SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ac65500c4902c35f15da2b0e61df6fb8defc1b5f01b09764ca4d929af0271ef3' 
  AND token = 'sLD9OOh5gsNKzUprMuqcIGuHajpEXpTrGQSmIntM7ME=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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