SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '806811aa0cca426422f102cd0d65d0056fef78f55473d8c60a943da2b9e3eae5' 
  AND token = 'c9Glf8KX2295Spn/rWHbEZXWgqCZVz/Q5SUUw9w68uA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

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