SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '0e4c55c45a99266d894c753b2261df406bc219af13e262103b3819ad6d25f4bd' 
  AND token = 'k40LPlvDQuC4jnYSE/KVG9GT5QLg2YIYrppgPatmaIw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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