SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6d284279793da27f02b81a9d005dc9160081762f965cc38768f63a75b04bde4d' 
  AND token = 'w1Na1pL6gOU5SlhBO8bsDQYjOr/KxchZtajwNd6WUvQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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