SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'df84fef4fab48c6ec7b6f169b9e37b05303af38d1f341b60c2e296d0f5360387' 
  AND token = 'zf+yAKd7MmVK1Y4P/1rrkdjVbYQ914iszA/EP+iUTac=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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