SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '6ec045539eedf6f612850145d3d77f10b3d0f936156e4fd95a3f4c3a819d3003' 
  AND token = 'bFYLHEMpTBCv7iAo3T3gPi+ehmR99xvs9buiYL/WEgc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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