SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '050afda8d38aa202bb311adca3f2bf96e1b068ae142f5556a32ffa6bb5cf49b6' 
  AND token = 'fdWF0f2nz/9pG94SOl2ySxxLJyxVQ8UXWmre4KohaG8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}