SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4a2f44dceb841d8ef6d6fac6f04b8789c4c4e6508d15aa0d53c1e3bb110d291e' 
  AND token = 'qOcqjhKyU7THlsBweMIRakUqK4TPrZmuVVgC5tYzrhc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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