SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1812e3576a5fc3ed9fd22ac854baf0a26ed8b1e3106f19f10d8f5e7bd30a430e' 
  AND token = 'wC+LEk+qIkVD6XrAGy1zSXcPM/KWr+plcPBo9pJN2X0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00045

JSON explain

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