SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c74aa5f98a5f484020133bfa87c312c7c7dcd196a5057fb62d3073d6be4eb162' 
  AND token = 'J4FqeLmU/BiXAMjuPUv0BK/fIi1C3Z66pUXPr+MNPto=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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