SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e6a0a34485ce3879b956ab8a2cd3ef9bd11406874e204e8c8782e687227899a9' 
  AND token = '6WY/2veQW6GbeGlFTihS5YPjjBSEIKreqOuiAbW9LBE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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