SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '7db88d9984d400bd862e3cb6cd4e1a87a3d1dac4f81f491a867a6dac3dac59eb' 
  AND token = '5ZkEpW0e+dhptXaNTRdw+nLSiD+16/dsuN9NrWJsMJs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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