SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '91e0cd2878c7b45254cfced492dd93cf18fc859b94343ce79669628aeb948f6a' 
  AND token = 'qSFgmSwnRFYoW3PEfAVA/5D5X/nGTyn++UMyL4v0Fws=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00045

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}