SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '4db57b309b10f26d55b047ef56377419d00fa2104335fbc999cf1cc537b4dca5' 
  AND token = 'Tgj6FWrElcNmRtrFqpB8lG3rygPo75nBJwDAflh+4QU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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