SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3480e0cb2cef693d640f5b09892e8511c8eecc80c4990c92ae077d2d2c671814' 
  AND token = 'AJLUZB59iroisueu/IvpmtxgK4FV6UzMhVG6TlyufU0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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