SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '62790bcf90e347794dad3b928f992685d4edf392b61a711f646b7b3a7ab22299' 
  AND token = 'L3tXWvohSTBm3Zq6IVFYQRv6iNoK5HLRr06jx+OeK8c=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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