SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '6fde84e970bcf7a80a2507b9576529f30a2b7338827b5191f3c93f5105e82e87' 
  AND token = 'sc/Qezf2NDSO7aZceaCL4s042k980hlCbq2KVHBsQ6M=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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