SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f8f67af6d56ea0b3f670a0a9ce0650284bef1cec9766892016bb0cf486fc7308' 
  AND token = '0OcYu9lZ8DAjWN9MUHho/GGrLnJdBJDiJW2jQlDyz+M=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00014

JSON explain

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