SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '3a637240d7a33e29e3909c7766d507db2d54deb4c1ecbf68da54e118e5de5f30' 
  AND token = 'l0UzQ+1EOzm5hs1VZwB2FQBtzRdcFJpCuu8n1G623HI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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