SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '78650a569531dbdc0aba57e91eaf53bfc7c641421afcf35b2696cb0487175bd8' 
  AND token = 'JJIkMqCrFLUDp2K5ErsBKp1rFQdtR0UPunLPTWMjrW0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00010

JSON explain

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