SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '62612f8c88aacf28f6001773a38d12e64530418d33107b22082d2a5cb4df08e6' 
  AND token = 'r92StsHVXqCUxt5aVC8kXfTtFQ7wljOBOEjU0DH+rYA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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