SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '8db3bd4bc85e39e346d1f1d1fa49306bc42b2f4a6e4050ce8a886925cd95f11d' 
  AND token = 'g0EFViQ+nMpiOmIfm8djcLdXsRxK7qSglMCmBVb0Jw4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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