SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5d6674682003ae53e983dc24f42ba16855c94048270be3b0f38a78d957fc81c3' 
  AND token = 'Lm8iMfiAgG1QwKTvphXXGHZBlaIm94OC1j+3kF0YZU0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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