SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0048854c6232542942c8318e2a20fe7c0f38a72fd6f111179f947b374714d6c1' 
  AND token = '7hePCnrzYrLH6cocK/LEu5kZvgz41+yVrJVGVLvm9ho=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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