SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '89fe9578a57d74c09670d9a3c116117d1c43a84233b65e0e079062abf4d2c511' 
  AND token = 'xixvLzhx1DlUNw+f+D+zTUQwelubZ7AsU33LJ5uqVHA=' 
  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"
    }
  }
}