SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '50358c535b6a5d669a8d5aabd290bc9cb982844a326f8a3a602d779f550b73b7' 
  AND token = '2QdPMpoa6iyqkCJ0g4iQw/S1fXMih0KmJSOSlY/HkHk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}