SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fba73c22d6df2575b116c470926ca32a9ed25573fc5a6293e914d01d9e0011b3' 
  AND token = 'L4kqUsBcFNkWYfOemfMs54azJyRx+nSROU0lZLpqwp4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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