SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'c0df24f9b685ffbc35679fab17a0c94d4668a6e2c51431138283ec5e7d7bc0da' 
  AND token = 'PyakRRmiY+OudCcg2reT+wAS1VyEy40pQ26lCWV3p/8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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