SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '07d3beef49a148758f521ac2f07cedfa92c2453b0efd920458665841d5f569cd' 
  AND token = 'vdNr2AemDs3IoEutH97F9UqMVujWyuvAvPAaxfbpzvc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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