SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '42dfc9a17530167beb7030012f914e50665d618626a1865cac105ca3f99e8f68' 
  AND token = '0cRztN4RNWO6ik7LSfAkG75I6wSMPyedOFEjRTKfQMM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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