SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '9710352b0a874bffdc9a73058c0d3361aeae6289cd6c4f200edcbf29d1d6a998' 
  AND token = 'Z3z+wB92NABf/NDT2iJmrJOmBCnLSGya3+wclFGHWWs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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