SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f964b45345835cae3a280ef0d6e01ba8df5026b728e67027b946defcf5b24517' 
  AND token = 'hC0l+1tkp+rNihPadn1uKHCl8TBxhliTe4jRVkTeE6Q=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}