SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'e313e403c5ec1986cd15acd701db0cabaf7acab4fe386e5c50648c76f48fdbe8' 
  AND token = 'KpezrG/aPdnjoOLy6+drTJwHTW3ajzmPvmUiNyPpg/k=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00053

JSON explain

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