SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5960a1a37569c2442a363f5edb34264355ae70585fda51ce7ad303402ea609c6' 
  AND token = 'XSrAqih/kOOsF1P2ZUeb0v4u/P9ps4cuGGrScXshFNM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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