SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0abbb3b48a9cf193327ec1a6bd25b64b6b7da676f054de066315b1b866fbe423' 
  AND token = 'zQ6Bx+o/GxID7JCiiusp73KTm4150COyeeiCy3/789U=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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