SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '19b546735310a4686c2b2191f6d0e77691cbb2bf29494a2553a2b6d2864c17c1' 
  AND token = 'RZ+/PXadkM1FYzLLFEF8UfAXUJPSWGMiyoGMcAvmrA8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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