SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4dd9834dbc3dabb20d7a4a65005314b95ce59f334859a80bb2086d5b042ff756' 
  AND token = 'NC76rKntpylpqhsbD4r/NX9wjGE1UOEJbkwumrcU4Zw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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