SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '622bead1876001654236f20be84fba6bafbcd5f8e31a443d09fe8cff60d3d651' 
  AND token = 'LdCryPCcsMpqOy0u90BjkOsiZwQkfbkP9wR+lBRVZdA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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