SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2870177af6c89c10d14869db535568b3cdb9d246b0acbab95bb12586d2f2a4e6' 
  AND token = 'jH70YJOw/XR7NaP6huuvo5RF4xV4OnQspE+m7EigLoY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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