SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6bd586437c1a757a927fed812a4c3f2b4a09c569c24a60dfdfd6ad37d43d109f' 
  AND token = 'AeLVZYvsOK3iu5HGhNUmPHXouukiPR0eBSKqrqElCLw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

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