SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'be0fef43e3d2b6d513dbd5e442ccc2def6ca8d0f2e2f6539b337788cba163f68' 
  AND token = 'nwoaitvVKkI4/2XbjzUPFOoojau3eViIQws+cbhmLKU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00014

JSON explain

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