SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '507b946724a9d49d2f6c7d4fd483a910863b36beddc39c14d36bc1cbac2961ce' 
  AND token = 'qzG3/A4Iq5T1clSpcdKie/XESFfjVojOBhYaXIWQV3I=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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