SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'c9574caf5a3832e57779d2a60627293a550934d24867f1cf98993c0983589a77' 
  AND token = '7lxLYJylUruJgR4tphLOj1C4Fh4Mv6mSbDQasLfBA8g=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

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