SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '7409d9803305b1163e05676d9342aadb0b3b4651dca5648e410efbd9fb4b13dc' 
  AND token = 'aQ3ngVO0UYlPdLAnMoS5dOC8Mz8e/od89mU766fLyGI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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