SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '5e2710a7a12f1b99730d54d1af6686f2f57059a9e9e565234dade0a8f2c9293b' 
  AND token = 'Xdr0iyhrsPsyG52fVhuF90zdvhAFz0FB0YqXvRCn8nM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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