SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '45c3fbd3a8c1a06c8d91f146e64275b8f622aee5d452b1e0e0cda7a556a142a8' 
  AND token = 'gnPhKR76yemeAzIjvr4s7vA4RkpFgtysBd/igOYWTdU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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