SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '52a4c95bd76ff6afa4bc5314acd63dd67efb0216593a4d6cffbc8c6dd469b94f' 
  AND token = 'G0r9XLXQ2ngSK1EuhBRVpfsBbHJS4nDLhvTGdMCTpjQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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